It is well known that many substances, whether gaseous, liquid or solid, tend to expand when heated. Although there are exceptions, most gases and liquids (under constant pressure) tend to expand when heated. Most metals also tend to expand when heated. This tendency of liquids and gases to expand when heated is utilized in producing power from heat. One common example is the steam engine. Also, it has been proposed to produce power from differentials in temperature by the tendency of some solids to increase in size when heated or cooled. The invention disclosed and claimed herein relates to power produced by the application of differentials in temperature to metal belts.
This invention relates to the art of heat engines and particularly to one of a type utilizing thermal expansion and contraction of metal belts to effectuate its actuation.
It is an object of this invention to provide a relatively simple heat engine which has a minimum of moving parts and which operates directly upon the application of heat to portions of one or more continuous metal belts so that such portions of each belt lengthen due to thermal expansion; while other portions of each belt are cooled to cause such portions to shorten due to thermal contraction. The belt or belts are passed around pulleys which are caused to be rotated by the action of the belts as different portions of such belts lengthen and shorten.
It is another object of the invention to provide an improved heat engine of the type mentioned whereby only a temperature differential is required without requiring a high combustion temperature as in a gasoline or other fuel type engine, although devices of my invention are also operative with such high temperatures.
It is another object to provide such a heat engine wherein each continuous belt which is lengthened and shortened in different portions by thermal means is wrapped around a pair of oppositely positioned pulleys of different diameters, one pulley being of slightly smaller diameter than the other. The pulley shaft of each pulley is connected to a pulley shaft of the pulley of another pair to assure the same angular velocity of the pulleys, although the linear velocities of the belts change throughout their lengths due to their lengthening and shortening.
Other objects and advantages of the invention should become apparatus upon reference to this description and claims and to the accompanying drawings.